Railroad car journal oil



Patented Oct. 3, 1933 UNITED STATES PATENT ,orrics RAILROAD CAR JOURNAL OIL v Thomas F. Ott, Berkeley, Calif., allignor to Union Oil Company of California, Los Angeles,

(Edit, a corporation of California 4 Claims.

This invention relates to a lubricating oil which is adaptable for use during extreme tempera ture conditions. More particularly, it relates to a lubricant such as a railroad car journal oil 3 which is capable of eflicient operation at temperatures varying from 100 F. or higher to 50 F. or lower.

An object of this invention is to produce allweather lubricating oil whose efliciency is unimpaired at'the extreme temperature ranges to which lubricants such as railroad car journal oils are sometimes subjected.

Another object is to produce a lubricant whose viscosity does not increase to so great an extent by cooling as to render it unflt for use at low temperatures. Furthermore, its viscosity does not decrease to so great an extent by heating as to harmiully aiiect its lubricating properties at high temperatures.

A further object is to produce a lubricating oil having'a very low pour test, for instance, a lubricat-ing oil having a pour point of F. or below and which also has sumcient viscosity at 100 F. to operate efliciently when subjected to temperature of about 100 F. or higher.

Another object is to produce alubricating oil which has a Saybolt Universal viscosity at 0 F. not above 2000 seconds, a viscosity at 100 F. not below seconds and a pour point not above -60 F.

An additional object is the production of a lubricating oil such as a railroad car journal oil by blending a mineral oil with a fatty oil whereby the inherent lubricating properties of the mineral ofl are enhanced by increased oiliness and film stability and by a decreased coefllcient of friction.

Up to the present time lubricating oils produced for use at summer temperatures; e. g. 100 F. or higher, are relatively ineiiicient for use at low temperatures because the viscosity rapidly increases with a temperature decrease to the extentthat itslubricating value, or oiliness becomes negligible. Conversely, up to the present time, the oilsdestined for use as lubricants at winter'temperatures could not be efllciently employed at high temperatures because of the extreme fluidity of these oils at high temperatures. These difliculties are especially apparent when a lubricant must be used under conditions in which large temperature fluctuations occur. For instance, the lubricating oil in railroad car journals must be adaptable for eillcient service under wide and varied temperature conditions and must be capable of satisfactorily operating even when the atmospheric temperature varies quickly and .severely.

It is well known that railroad car journals are lubricated by oil absorbed in cotton waste or the like and that the failure oi'the lubricant re- 60 suits in hot boxes' with their consequent delays and dangers. 11 oil adaptable only for cold weather is employed, an increase in temperature reduces the viscosity of the oil to so great an extent that it becomes too fluid and loses its necessary property of oiliness. It oil adaptable only for warm weather is used, a decrease in temperature increases its viscosity and the cotton waste or other stufling in the stuiiing box balls or rolls and the car journal cannot be properly lubricated. 7 In order to ensure that the oil will lubricate. at the low temperatures I have found it advisable to devise an oil which has an extremely low pour point. This will ensure fluidity at these very low temperatures,

Another object of my invention, then, is to produce a railroad car oil which does not have these objectionable characteristics and which operates efllciently at both high and low temperatures.

Another diiiiculty encountered up to the present time is that lubricating oils change their characteristics during use as lubricants, particularly during use at high temperatures, whereby the lubricating qualities of the oil deteriorate, It is believed that oxidation of the oil is responsible for the gum formation and other changes that occur and for the deleterious reactions which take place within the oil.

A further object, then, is to make a lubricating oil which does not have a tendency to change in characteristics during use, as by oxidation while in service.

An additional object is to economically produce a lubricating oil having these desirable charac- 5 teristics.

-My invention relates to a lubricant which has a relatively flat viscosity curve under extremes of temperature; that is, a lubricant whose viscosity remains relatively unaflected by tempertaure 1 changes. It has a sufllcient body or viscosity at high temperatures, such-as F. or higher, to properly lubricate at the temperature and the same oil also has the ability ,to lubricate as a fluid at low temperatures such as 50 F. at which temperatures the viscosity of the oil has not increased to such a degree as to impair its lubricatin value. Previously, cold weather railroad car journal oils at 0 F. had a viscosity as high as 10,000 seconds Saybolt or even in excess of this 1-10 figure. My lubricating oil may have a viscosity at F. of 2000 seconds Saybolt or less and a viscosity not below '10 seconds Saybolt at 100 F. In other words, it is not necessary that the viscosity of my lubricating oil be abnormally high at 0 F. in order that it may be of sufficient viscosity at high temperatures such as 100 F. Furthermore, my lubricating oil having these viscosity characteristics may have a pour test not above F. Therefore, itis not necessary that the viscosity of my lubricating oil at 100 F. be abnormally low in order that it may have a pour test below --60 F.

This new and improved lubricant is prepared by blending a mineral oil with a fatty oil. The components of this lubricant have been selected for their special qualifications which give to the final product those characteristics set forth above in the objects of this invention. Preferably, the mineral oil to be blended has a viscosity of 50 to seconds Saybolt Universal at 100 F., for instance 57 seconds at 100 F. and its viscosity at 0 F. is about 1000 seconds Saybolt. The mineral oil remains fluid at 30 F. or lower.

The fatty oil which I may employ may be-a blown fatty oil such as blown rapeseed oil. As stated above, the presence of fatty oil enhances the inherent lubricating properties of the mineral oil by increasing the oiliness and fllm stability and by decreasing its coefilcient of friction. This fatty oil may have a viscosity of from 1000 to 2000 seconds at 210 The use of such fatty oil in blending my lubricant enables me to employ a mineral oil having relatively high viscosities at higher temperatures, such as'100" F. and yet obtain a lubricant having a low pour test. Stated diiierently, by blending a fatty oil, preferably blown, with a selected mineral oil, I am enabled to produce a lubricating oil having eflicient lubricating value at either low or high temperatures.

Ihave found that lubricants comprising fatty oils mixed with mineral oils are subject to oxidation, especially when used at high temperatures,

and that the lubricating value of the composition selected for its ability to withstand oxidation at high temperatures This oil may be compounded with a fatty oil or with an oxidized fatty oil to produce a lubricant having the desired qualities.

Many mineral oils tend to oxidize when exposed to high temperatures for a short time, or even i when exposed to moderate temperatures overa long period. In order to maintain the character: istics of the mineral oil during the use of the lu-,

bricant at these temperatures, I prefer to select a mineral oil which is not easily\ oxidized and whosecharacteristics are not easily changed by use. I have discovered that a suitable mineral oil having these qualifications can be obtained by the well known treatment of mineral lubricating oil with liquid sulphur dioxide as, for instance,

in the manner disclosed by Lazar Edeleanu in the United States Patent No. 911,553, issued Feb.

2nd, 1909. This treatment removes substantially all of the unsaturated and aromatic compounds which, I believe, are the components in mineral oil which are the most subject to oxidation or change during use. I have also discovered that the removal of such compounds from mineral oil also affects the relationship between the viscosity and temperature of the oil, thereby producing an oil that possesses a lesser tendency to thicken or increase in viscosity as the temperature is reduced.

In some cases it may not be necessary, in operating according to my invention, to use mineral oil which has been subjected to treatment with liquid sulphur dioxide. This, however, is my preferred embodiment especially when my oil is obtained from naphthenic base crudes such as California asphalt crude. Thus, the petroleum lubricating oil which I blend with fatty oil may be that portion of lubricating oil obtained from naphthenic base crude oils which is substantially insoluble in liquid sulphur dioxide. Untreated mineral oil may be compounded with oxidized or blown fatty oil and good results can be obtained. Also, a mixture of unoxidized and oxidized fatty oil may be employed with mineral lubricating oil which may or may not have been subjected to treatment with liquid sulphur dioxide. Also, a mixture of mineral oil with an unoxidized fatty oil could be used by proper selection of the type and amount of fatty oil employed. Each and all of these modifications are within the purview of my invention.

By the term "fatty o I mean to include animal, vegetable or fish oils such as cottonseed oil, lard oil and the like. One or more of these oils may be selected for blending with the mineral oil. In my preferred composition, I select oxidized rapeseed oil. The fatty oil may be oxidized in the usual manner, as for instance, by air blowing to produce blown oil.

As an example illustrating the composition of my lubricating oil, I may blend a mineral oil having a viscosity of 57 seconds at F. and of 1000 seconds at 0 F. and a pour point not above -30 F., for instance 40 F. with 6% of an oxidized or blown rapeseed oil having a viscosity above 1000 seconds Saybolt Universal at 210 F.; for instance, having a viscosity of 1500 seconds Saybolt' Universal at 210 F. This mixture ex hibits. a viscosity of 72 seconds at 100 F. and a viscosity of 1700 seconds at 0 F. This 011 also has a pour test of -70 F. The mineral oil may or may not have been treated with liquid sulphur dioxideprior to blending with the oxidized fatty 12b oil. In general, I have found that mineral oil which has been freed from unsaturated and aromatic bodies is superior to oil which has not been subjected to this treatment. It is, of course, evident that the example may be widely varied and yet be within the scope of my invention.

In addition, by employing an oxidized fatty oil, such as oxidized rapeseed oil, in admixture with a low viscosity mineral oil obtained from naphthenic 1 base crudes such as California asphalt crudes, I have discovered that it is possible to produce a lubricant whose viscosity is lower at 0 F. and higher at 210 F. than the viscosity of a straight mineral oil having the same viscosity at 100 F. as the viscosity of the blend at 100 F.

By a straight mineral oil, I mean one which is unblended with a fatty oil or a blown fatty 011.

For instance, a straight mineral oil obtained from California asphaltic crude oil, untreated with sulphur dioxide, may have a viscosity of 3300 seconds at 0 F., '72 seconds at 100 F. and 35 seconds at 210 F. Such an oil may have a pour test not below -55 F. A straight California mineral oil, treated with liquid sulphur dioxide, as described above, for removal of aromatic and unsaturated compounds having the'same viscosity of 72 seconds at 100 F. may have a viscosity of 2200 seconds at 0 F. and-36 seconds at 210 F. This oil may have a pourv test of -55 F. My blended oil, also having the same viscosity of '72 seconds at 100 F., may have a viscosity of 1700 seconds at 0 F. and 37 seconds. at 210 F. This oil may have a pour test of -'70 F. or lower. Thus, it is also evident that I can produce a lubricating oil whose pour test.is lower than the pour test of a straight mineral oil having the same viscosity at 100 F. as the blend; Furthermore, in addition to the fact that the sulphur dioxide treatment of the California asphalt base mineral oil component of my blend removes the unsat-.

urated and aromatic bodies and thereby produces a mineral oil which is not so readily oxidizable, there is also the added advantage that the sulphur dioxide treatment enables me to use a mineral oil whose viscosity at high temperatures is relatively high and yet which is not excessively viscous at low temperatures and whose pour point is low. When such an oil is blended with fatty or blown fatty oils, the viscosity at high temperatures is maintained or even increasedwhile the viscosity at low temperatures is reducedand the pour point of the blend is lower than the pour point of the mineral oil alone.

The temperature at which an oil congeals is commonly referred to as its pour point and the values recited herein have been obtained according to method D 97--2"I T of the American Society of Testing Materials. The measurements of vis-. cosity referred to herein are based upon the American Society of Testing Materials,-method- D 88-26, using a Saybolt Universal viscosimeter.

It will be understood that the foregoing is merely illustrative of a preferred operation of the invention, of which many variations may be made by those skilled in the art without departing from viscosity at 0 F. of approximately 2000 seconds,

a minimum Saybolt Universal viscosity at 100 F. of approximately 70 seconds, and a pour point not above approximately 60 F.

2. A lubricant as defined in claim 1 wherein the fatty oil is an oxidized fatty oil.

3. A lubricant as defined in claim 1 wherein the;

fatty oil is an oxidized rapeseed oil.

4. A railroad car journal lubricant comprising approximately 6 parts by weight of a blown fatty oil having a viscosity within the range of 1000 to 2000 seconds Saybolt Universal at 210 F. and 94 parts by weight of a mineral oil which is substantially insoluble in liquid sulphur dioxide, which has a viscosity within the range of 50 to 65 seconds Saybolt Universal at F., and which has a pour point of not above 30 F., said lubricant being characterized by a maximum Saybolt Universal viscosity at 0 F. of approximately 2000 seconds, and a minimum Saybolt viscosity at 100 F. of approximately '70 seconds, and a pour point not above approximately .60 F.

THOMAS F. OT'I. 

